Condylar and disk position and signs and symptoms of temporomandibular disorders in stress-free subjects

BACKGROUND: The authors conducted a study in subjects who tested free of psychological stress to determine the position of the condyle and whether that position was related to signs and symptoms of temporomandibular disorders (TMDs). METHODS: Forty subjects underwent psychological evaluation to ensure freedom from psychological stress. The authors evaluated tenderness of the masticatory muscles and temporomandibular joints (TMJs) by means of bimanual digital palpation, and they determined the positions of the condyle and disk by using magnetic resonance imaging. RESULTS: A total of 23.75 percent of the condyles were displaced away from the centric position either anteriorly (3.75 percent) or posteriorly (20.00 percent). chi(2) analysis showed a relationship between the position of the condyle and displacement of the disk, as well as a relationship between the position of the condyle and tenderness of the TMJs. CONCLUSION: Although these relationships proved significant, it cannot be assumed that displacement of the condyle away from the centric position is predictive of TMD. CLINICAL IMPLICATIONS: Only two subjects were judged to have had TMJ internal derangement. Thus, the absence of psychological stress seems to have played a role in this finding.     

Study of the signs and symptoms of temporomandibular dysfunction in individuals with normal occlusion and malocclusion

The signs and symptoms of temporomandibular dysfunctions were studied in a well-defined sample, divided into one group with normal occlusion and a second group with malocclusion, where the primary characteristic was Angle Class II a malocclusion with moderate to deep overbite. Each group comprised 30 individuals with a mean overall age of 22.6 years. The following were evaluated in both groups: tenderness to palpation of the muscles involved in the joint; presence of articular noises; subjective symptoms obtained via a questionnaire; and mandibular movements. The data gathered was subjected to statistical analysis and no significant differences were detected between the groups in the majority of variables studied. However, it was found that those individuals with malocclusion had a wider range of lateral movement and also complained of greater discomfort in the TMJ when compared to individuals in the normal occlusion group. The lack of uniformity between the results of this work and those of other authors may be attributed in particular to variations in age of the sample populations studied.     

Condylar position as a predictor of temporomandibular joint internal derangement

Scout tomograms and arthrograms of 243 patients were separated and numbered. The location of the condyle within the fossa in the closed-mouth position was assessed by means of three evaluation techniques. Later, the arthrograms were interpreted and matched with the corresponding tomograms to evaluate the relationship between posterior displacement of the condyle and anterior displacement of the articular disk. The position of the disk within the fossa was found to be extremely variable whether disk position was normal or abnormal.     

Muscle thickness, bite force, and craniofacial dimensions in adolescents with signs and symptoms of temporomandibular dysfunction

Ultrasonography has been used to determine the association between muscle thickness, temporomandibular dysfuntion (TMD), facial morphology, and bite force. The aim of this study was to evaluate signs and symptoms (SS) of TMD using the craniomandibular index (CMI), masseter and anterior temporalis thickness, facial dimensions, and bite force in adolescents (12-18 years of age): 20 (10 males and 10 females) with SSTMD and 20 without (control, matched for age and gender). Ultrasonography was carried out using Just-Vision 200, and bite force measured with a pressure transducer. The measurements undertaken on the cephalograms included anterior (n-gn, n-Me, sp-gn) and posterior (S-tgo) facial dimensions, jaw inclination (NSL/ML), vertical jaw relationship (NL/ML), gonial angle (ML/RL), and overbite and overjet. The data were analysed with analysis of variance, Pearson's and Spearman's correlation and multiple regression. The SSTMD group showed a smaller bite force than the controls (P < 0.05). In the control group, bite force was negatively correlated with jaw inclination and overbite. There were negative correlations between anterior temporalis thickness and anterior facial dimensions; and positive correlations for masseter and anterior temporalis and posterior dimensions. In the SSTMD group, there were positive correlations for masseter and bite force, and anterior and posterior dimensions. Negative correlations were found for the masseter and temporalis muscles and jaw inclination and vertical jaw relationship. Multiple regression analysis showed that in the control group the overjet and jaw inclination contributed 50 per cent to the variance in bite force. In the SSTMD group, the dimensions of the masseter muscles during contraction contributed 39 per cent to the variance. The correlations between CMI and the craniofacial variables were more significant in the SSTMD group. The findings indicate that muscle thickness influences facial dimensions and bite force in adolescents with SSTMD.     

No heritability of temporomandibular joint signs and symptoms

The causes of temporomandibular joint (TMJ)-related signs and symptoms are largely unknown. We tested the hypotheses that these signs and symptoms, as well as oral parafunctional habits, are substantially heritable. Questionnaire and clinical data were collected from 494 twins, including pairs of reared-apart and reared-together monozygotic (MZ) and dizygotic (DZ) twins. A history of joint-area pain, joint noises, and clenching and grinding habits was scored as present or absent. Twenty-nine percent of the population experienced at least one sign or symptom. Nearly one-quarter of subjects clenched or ground their teeth, and 8.7% reported a history of joint-area pain. Pain was associated with clenching, grinding, and joint noises. MZ twins were no more similar than DZ twins for any outcome, suggesting that genetic factors do not influence these traits in the population. Reared-together MZ twins were no more similar than reared-apart MZ twins, suggesting a negligible effect of the family environment on these outcomes. Environmental factors unique to each twin appeared to be the major determinants of variation in this population.     

Condylar position in superior maxillary repositioning and its effect on the temporomandibular joint

Twenty-nine patients (58 joints) were tomographically evaluated for condylar position and assessed for temporomandibular joint function following superior maxillary repositioning with mandibular autorotation. Seventy-six percent of the condyles showed postoperative posterior repositioning, whereas tomographic measurement of the joint spaces revealed significantly posterior condylar position (P less than .01) relative to the preoperative position. Pre- and postoperative comparative values of condylar displacement from absolute concentricity based on the Pullinger index also showed posterior condylar repositioning postoperatively (P less than .001). However, there was no correlation between condylar position and the presence of temporomandibular joint symptoms in both the asymptomatic and symptomatic groups.     

Epidemiology of signs and symptoms in temporomandibular disorders: clinical signs in cases and controls

An epidemiologic study of clinical signs and symptoms of temporomandibular disorders (TMD) was conducted with a probability sample of adults enrolled in a major health maintenance organization (HMO). This report presents data from a first wave field examination and interview conducted by trained, calibrated dental hygienist field examiners. Significant gender differences for vertical jaw opening measures were observed but no significant age differences were found for the distribution of clinically relevant findings. Clinic cases showed smaller amounts of vertical range of jaw motion but did not differ from community cases or controls on extent of lateral, protrusive, or retrusive mandibular movements; on classification of occlusion; or on dentally related variables. Clinic cases had more pain during all jaw excursions as well as during muscle and joint palpation. Joint clicking sounds were also observed more frequently in clinic cases.     

Condylar bony change, disk displacement, and signs and symptoms of TMJ disorders in orthognathic surgery patients

OBJECTIVE: We sought to investigate the relationship between condylar bony change and disk displacement with respect to the signs and symptoms of temporomandibular joint (TMJ) disorders in patients undergoing orthognathic surgery. STUDY DESIGN: We performed a cross-sectional retrospective study of the pretreatment helical computed tomography scans of 129 orthognathic surgery patients. RESULTS: Condylar bony change, unilaterally or bilaterally, was found in 35.7% of the subjects and 24.4% of the joints. Disk displacement, unilaterally or bilaterally, was seen in 41.4% of the subjects and 29.5% of the joints. The type of craniofacial deformity was significantly associated with condylar bony change and disk displacement. No association of clinical symptoms with respect to craniofacial deformity, condylar bony change, or disk displacement was found except in the case of TMJ sounds. CONCLUSION: The results suggested that craniofacial deformity might be related to TMJ disorders, but the only clinical symptom associated with types of craniofacial deformity was TMJ sounds.     

Comparison of the efficacy of a questionnaire, oral history, and clinical examination in detecting signs and symptoms of occlusal and temporomandibular joint dysfunction.

A comparison of three methods of obtaining information relating to some TMJ signs and symptoms has been made. The taking of an oral history by this examiner was shown to be the least reliable. The acquisition of data by this verbal process is a clinically sophisticated and difficult medical procedure and a major source of error is the bias or preconception that a clinician brings to his observations. Far more effective was a written, self-administered patient questionnaire, which proved quite reliable in detecting the presence of some occlusal habits. This study indicates that the initial use of a self-administered patient questionnaire, even in the hands of an inexperienced dentist, will ensure that certain essential data are obtained and recorded and will result in the discovery that a substantial number of patients have signs and symptoms of occlusal and TMJ dysfunction. The most objective method is of course the direct clinical examination. A combination of these three methods of obtaining information is recommended as an important part of routine occlusal and TMJ examinations.     

Frequency of temporomandibular disorder signs and symptoms among call center employees

Objective: The current study aimed to investigate the frequency of signs and symptoms of temporomandibular disorders (TMD) among call center employees.

Methods: Workers from four call centers (CC) were invited to participate in this study. The examination was based on the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD). The tenderness of the masticator muscles was assessed on both sides by bilateral palpation. The mobility of the mandible was measured with a plastic millimeter ruler on opening, lateral excursions, and protrusion.

Results: In total, 124 call center employees with a mean age of 28.61 ± 4.71 (between 22 and 47 years of age) were enrolled in this study. There was no statistically significant relation between the numbers of calls answered in a day and teeth clenching, teeth grinding, earache, tinnitus, or pain on yawning/chewing. Only protrusive movement pain and joint noise were significantly higher among employees who answered more than 140 calls/day (p < 0.01). An evaluation of the TMD signs and symptoms in relation to job stress level revealed that job stress level significantly affected the incidence of headaches among call center employees (p < 0.01).

Conclusion: The present study demonstrated no statistically significant relation between TMD signs and symptoms and call center employees except protrusive movement pain and joint noise. This relation was seen only in the employees who answered more than 140 calls per day. Headache, teeth clenching, and TMJ noise were the signs and symptoms encountered most often in this study. Multicentered studies in different geographic locations should be conducted to eliminate the limitation of this study.     

Five-year longitudinal study of adolescents with intact and restored dentitions: signs and symptoms of temporomandibular dysfunction and functional recordings

Signs and symptoms of temporomandibular dysfunction (TMD) and functional recordings were re-examined in subjects, 19-21 years of age, 5 years after the first examination. Thirty-seven subjects had restored dentitions at both examinations (group F), 13 subjects with previously intact dentitions had had fillings in their teeth during the follow-up period (group FI), and 14 subjects had intact dentitions at both examinations (group I). In agreement with the first examination, the subjects with restored dentitions had a higher degree and frequency of TMD than the subjects with intact teeth. Most of the symptoms were mild, but more severe symptoms were reported by the subjects in group F, and female subjects in group F had more signs than male subjects. The subjects who had received fillings during the follow-up period (group FI) constituted a group intermediate between group F and group I with regard to signs and symptoms of TMD. Frequent parafunction and more attrition were more common in group F. Together with the finding of increased muscle tenderness, this indicates more functional activity in restored dentitions. Correlation analysis did not reveal any relationship between occlusal factors and TMD. The findings of this study are consistent with those of the earlier investigation. Dental filling therapy appears to be an aetiological factor in TMD worthy of more consideration and more extensive research.     

Comparison of Bennett shift measured at the hinge axis and an arbitrary hinge axis position

Bennett shift was measured at an arbitrary hinge axis position and at the hinge axis position in 10 subjects. Sixty percent of the arbitrary hinge axis positions were within 5 mm of the hinge axis position. There was no significant difference in the Bennett shift measurements made at the hinge axis and the arbitrary hinge axis positions when measured in 0.25 mm increments. The average immediate Bennett shift was found to be 1.05 mm on the left side and 1.12 mm on the right side when firm guidance was used.     

Arthroscopic TMJ surgery: effects on signs, symptoms, and disc position

Nineteen subjects with documented intra-articular pathology refractory to nonsurgical therapies underwent temporomandibular joint (TMJ) arthroscopy involving lysis and lavage in the superior joint space. Following surgery, subjects were evaluated for 6 to 12 months by clinical examinations and questionnaires at designated time periods and by postsurgical joint imaging. Significant improvement was noted in pain, mandibular movement, and diet. No improvement was noted in the incidence of joint sounds, and disc position was unchanged in 80% of the joints. The findings suggest that disc repositioning may not be needed to achieve clinical success.     

Oral parafunctions,piercing and signs and symptoms of temporomandibular disorders in high school students

Objective The use of chewing-gum and piercing has become common among adolescents and might result in increased oral muscle activity and overloading. Aim To investigate the frequency of oral piercing and parafunctions in relation to symptoms of temporomandibular disorders (TMD) among adolescents. Materials and methods One hundred and twenty-four third level high school students, living either in a city or in a small town, enrolled in either science or media programmes, were included. The students completed a questionnaire regarding different parafunctions and symptoms of TMD. A clinical examination of the temporomandibular system and estimation of the tooth wear was performed in 116 students. Results Chewing-gum was used by 86% of the students (25% with a daily use) and 14% had an oral piercing. The science students used more chewing gum than the media students (p?=?0.008), while the media students had more piercings (p?p?=?0.007) and more severe symptoms (p?=?0.003), had more medical consultations and used more analgesics (both p?p?=?0.01) than boys. Girls had more oral piercings and used more chewing gum than boys (both p?p?p?p?p?p?p?p?=?0.004). Conclusions There is an association between use of chewing gum, nail biting, oral piercing, and symptoms of TMD.     

Full-mouth rehabilitation following treatment of temporomandibular disorders and teeth-related signs and symptoms

The literature is replete with theories regarding temporomandibular disorders (TMD). However, there is a paucity of information concerning perceived malocclusion and other teeth-related signs and symptoms after full-mouth rehabilitation. This clinical study was designed to evaluate the perception of TMD patients concerning perceived malocclusion and other teeth-related signs and symptoms after full-mouth rehabilitation guided by the Mental Analog Scale (MAS). Among 38 patients referred for full-mouth rehabilitation, 20 were diagnosed as having TMD after reviewing a questionnaire, recording the major complaints and symptoms, in addition to performing comprehensive clinical examination. Nonsurgical therapy was performed, including fabricating an anterior programming device, a centric relation occlusal device and finally full-mouth rehabilitation by means of placing crowns on all upper and/or lower teeth. All full-mouth rehabilitation procedures were performed using a fully adjustable articulator and mandibular movements were recorded following pantographic tracings. After full-mouth rehabilitation, the patients were followed up at 1, 2, 4, 6, 9, and 12-month intervals, and the major signs and symptoms were recorded along with adjunctive teeth-related signs and symptoms. Fisher exact probability tests were applied to analyze the results (P<.05). Statistical comparisons of the MAS responses before and after treatment (at 1-month recall) showed significant improvement (P<.05) for all teeth-related signs and symptoms except for bruxism (P=.0699). Further improvement was noted at the 4-month recall period. However, these improvements were not statistically significant for all teeth-related signs and symptoms. No further change was noted after the 4-month recall period. There was a marked reduction in perceived malocclusion and adjunctive teeth-related signs and symptoms during function, only after performing occlusal equilibration of the final restorations.     

Longitudinal study of patients with TMJ dysfunction by tomographic examination: Condylar position and clinical sign

For patients with TMJ dysfunction, operators often change the condylar position by various methods. The aim of this study is to investigate how much the changes with time of condylar positions are related to the changes of clinical signs. The subjects were 584 joints of 127 patients with TMJ dysfunction to whom the serial lateral TMJ tomography was performed more than twice. In the most of cases where the condylar position had moved downward, inter-incisal distance had increased and TMJ noise had ameliorated. Furthermore, in many cases where the condylar position had moved forward, the amelioration of the TMJ pain was observed. It was considered that those ameliorations occurred because the positional relationship between the condylar head and the articular disk or posterior attachment had been improved.